Improvement in photographic printing apparatus



attent (Itjlitc.

JAMES n. HAMILTON.

0F -SIOUX CITY, IOW-A.

Letters Patent No. 101,728, dated April 12, 1870.

IMPROVEMENT IN PHOTOGRAPHIC PRINTING APPARATUS.

The Schedule referred to in the Letter: Patent and making part of the same.

This invent-ion relates to improvements in apparatus for making mezzotint photographs, and consists in the employment of a large box containing several square tubes, and supported on pivots in a frame mounted on casters, so that it may be adjusted in vertical and horizontal planes, to cause the tubes to receive'the rays of light from the sun in the lines of their axes at all times, and so as to fall on the negative perpendicular to it, the negative with the printing-frame being placed at the bottom of the tubes.

Figure 1 is a iiont elevation of my improved apparatus, and

Figure 2 is a sectional elevation of the same.

Similar letters of reference indicate corresponding parts.v

A is the box containing the square tubes B, and mounted on pivots C in the upper ends of the parts D, which rise up from a stand, E, mounted on three or more casters, F.

G represents curved slotted projecting plates, placed in the sides of the box for securing it at any point of rotation on its horizontal axis by the screw and thumbnut H.

I represents pockets at the bottom of the tubes, in which the printing-board is placed.

It will be seen that by turning the box on its axis,

` and the stand on the casters, the light may be always caused to fall upon the negatives perpendicular to' their planes.

'.lhese tubes, which are the size of the negatives, cut olf all reflected or diffused light, and, by reversing the negative, or placing a glass between it and paper, a beautiful effect is produced, without impairing the definition.

Besides ordinary work, it is valuable for printing porcelain pictures, which, owing to ine-qualities inthe surfaces of the negatives and porcelain plates, makes it almost impossible with the ordinary method of printing to 4produce a sharp picture, the contact being imperfect. With this apparat-ns this diiculty is removed.

In copying photographs, the, roughness of the paper which produces such a disagreeable effect in the ordinary method of print-ing is removed, and the copy has all the smoothness and rouuduess of a picture taken from life, and in landscape photography many beautiful eiiects can be produced, not attainable in any other way.

Having thus described my invention,

I claim as new and desire to secure by Letters Patent- A photographic printing-case, A, provided with the tubes B and pockets I, and mounted on'a stand, so as to oscillate vertically and horizontally, as herein shown and described.

The above specin'cation of my invention signed by me this 14th day of February, 1870.

JAMES H. HAMILTON.

Witnesses:

A. l, WILGosKI,

GHAs. GANDENBERGER. 

